Quasifree neutron knockout reaction reveals a small -Orbital component in the Borromean nucleus B

Yang, Z. H.*; Kubota, Yuki*; Corsi, A.*; Yoshida, Kazuki; Sun, X.-X.*; Li, J. G.*; Kimura, Masaaki*; Michel, N.*; Ogata, Kazuyuki*; Yuan, C. X.*; et al.

Physical Review Letters, 126(8), p.082501_1 - 082501_8, 2021/02

https://doi.org/10.1103/PhysRevLett.126.082501

A quasifree (,) experiment was performed to study the structure of the Borromean nucleus B, which had long been considered to have a neutron halo. By analyzing the momentum distributions and exclusive cross sections, we obtained the spectroscopic factors for and orbitals, and a surprisingly small percentage of 9(2)% was determined for . Our finding of such a small component and the halo features reported in prior experiments can be explained by the deformed relativistic Hartree-Bogoliubov theory in continuum, revealing a definite but not dominant neutron halo in B. The present work gives the smallest - or -orbital component among known nuclei exhibiting halo features and implies that the dominant occupation of or orbitals is not a prerequisite for the occurrence of a neutron halo.

Validation of the multinucleon transfer method for the determination of the fission barrier height

Kean, K. R.; Nishio, Katsuhisa; Hirose, Kentaro; Vermeulen, M. J.; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Andreyev, A. N.; Tsekhanovich, I.*; Chiba, Satoshi*

Physical Review C, 100(1), p.014611_1 - 014611_6, 2019/07

https://doi.org/10.1103/PhysRevC.100.014611

Proceedings of the 2016 Symposium on Nuclear Data; November 17-18, 2016, High Energy Accelerator Research Organization, Tsukuba, Ibaraki, Japan

Sanami, Toshiya*; Nishio, Katsuhisa; Hagiwara, Masayuki*; Iwase, Hiroshi*; Kunieda, Satoshi; Nakamura, Shoji

JAEA-Conf 2017-001, 222 Pages, 2018/01

JAEA-Conf-2017-001.pdf:30.89MB

The 2016 Symposium on Nuclear Data was held at Kobayashi Hall of High Energy Accelerator Research Organization, on November 17 and 18, 2016. The symposium was organized by the Nuclear Data Division of the Atomic Energy Society of Japan in cooperation with Radiation Science Center, High Energy Accelerator Research Organization, Nuclear Science and Engineering Center of Japan Atomic Energy Agency and North Kanto Branch of Atomic Energy Society of Japan. In the symposium, there were one tutorial, "Historical Evolution of Accelerators" and four oral sessions, "Overview of the ImPACT Program - Reduction and Resource Recycling of High Level Wastes through Nuclear Transmutation", "Facilities and experiments for nuclear data in Japan", "Nuclear data from measurement to application", and "Progress of neutron nuclear data measurement and research for its basics and application". In addition, recent research progress on experiments, evaluation, benchmark and application was presented in the poster session. Among 65 participants, all presentations and following discussions were very active and fruitful. This report consists of total 31 papers including 10 oral and 21 poster presentations.

Four-dimensional Langevin approach to low-energy nuclear fission of U

Ishizuka, Chikako*; Usang, M. D.*; Ivanyuk, F. A.*; Maruhn, J. A.*; Nishio, Katsuhisa; Chiba, Satoshi

Physical Review C, 96(6), p.064616_1 - 064616_9, 2017/12

https://doi.org/10.1103/PhysRevC.96.064616

Study of fission using multi-nucleon transfer reactions

Nishio, Katsuhisa; Hirose, Kentaro; Vermeulen, M. J.; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Sato, Tetsuya; Nagame, Yuichiro; et al.

EPJ Web of Conferences, 163, p.00041_1 - 00041_6, 2017/11

https://doi.org/10.1051/epjconf/201716300041

Experimental fission study using multi-nucleon transfer reactions

Nishio, Katsuhisa; Hirose, Kentaro; Lguillon, R.*; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Smallcombe, J.*; Chiba, Satoshi*; Aritomo, Yoshihiro*; Tanaka, Shoya*; et al.

EPJ Web of Conferences, 146, p.04009_1 - 04009_6, 2017/09

https://doi.org/10.1051/epjconf/201714604009

Fission fragments mass distributions of nuclei populated by the multinucleon transfer channels of the O + Th reaction

Lguillon, R.; Nishio, Katsuhisa; Hirose, Kentaro; Makii, Hiroyuki; Nishinaka, Ichiro*; Orlandi, R.; Tsukada, Kazuaki; Smallcombe, J.*; Chiba, Satoshi*; Aritomo, Yoshihiro*; et al.

Physics Letters B, 761, p.125 - 130, 2016/10

https://doi.org/10.1016/j.physletb.2016.08.010

Development of a measurement system for the determination of () cross-sections using multi-nucleon transfer reactions

Makii, Hiroyuki; Ota, Shuya*; Ishii, Tetsuro; Wakabayashi, Yasuo*; Furutaka, Kazuyoshi; Nishio, Katsuhisa; Nishinaka, Ichiro; Chiba, Satoshi; Igashira, Masayuki*; Czeszumska, A.*

Nuclear Instruments and Methods in Physics Research A, 797, p.83 - 93, 2015/10

https://doi.org/10.1016/j.nima.2015.05.005

We have installed new experimental apparatus to measure rays from highly excited states populated by the multi-nucleon transfer reactions with heavy-ion projectiles to determine the () cross sections by means of the surrogate reaction method. Apparatus consists of two anti-Compton LaBr(Ce) spectrometers to measure the rays and a Si - detector system to detect outgoing projectile-like particles. Reactions of 153-MeV O beams with Gd and Gd targets were used to study the performance of apparatus. By using the LaBr(Ce) scintillators with relatively large volume (101.6 mm in diameter and 127 mm in length), we have successfully measured rays from the compound nuclei, which have excitation energy above neutron separation energy, populated by Gd(O, O)Gd and Gd(O, O)Gd two-neutron transfer reactions. The present study has demonstrated high capability of apparatus to measure the de-excitation rays in the compound nuclei produced by the multi-nucleon transfer reactions for determination of the () cross sections by using the surrogate reaction method.

Development of anti-Compton LaBr(Ce) spectrometer for measurement of surrogate reactions

Makii, Hiroyuki; Ota, Shuya*; Ishii, Tetsuro; Nishio, Katsuhisa; Nishinaka, Ichiro; Furutaka, Kazuyoshi; Wakabayashi, Yasuo*; Chiba, Satoshi*; Igashira, Masayuki*

Nuclear Data Sheets, 119, p.361 - 364, 2014/05

https://doi.org/10.1016/j.nds.2014.08.099

Anti-Compton LaBr(Ce) spectrometers have been installed at JAEA-Tokai tandem accelerator facility in order to measure the rays from the highly excited states produced by surrogate reactions. Each spectrometer consists of a central LaBr(Ce) detector with a diameter of 10.2 cm and a length of 12.7 cm, and an annular BGO detector with a thickness of 2.5 cm and a length of 25.4 cm. In this contribution, we will present the results of performance test using the standard ray source and high-energy rays from the Al(p,)Si reaction, and a measurement plan for (n,) cross sections using a surrogate reaction at JAEA-Tokai tandem accelerator facility.

Dynamical model of surrogate reactions

Aritomo, Yoshihiro; Chiba, Satoshi; Nishio, Katsuhisa

Physical Review C, 84(2), p.024602_1 - 024602_10, 2011/08

https://doi.org/10.1103/PhysRevC.84.024602

A new dynamical model is developed to describe the whole process of surrogate reactions; the transfer of several nucleons at an initial stage, thermal equilibration of residues leading to washing out of shell effects and decay of populated compound nuclei are treated in a unified framework. Multi-dimensional Langevin equations are employed to describe time-evolution of the system. The new model is capable of calculating the spin distribution of the compound nuclei, one of the most important quantities in the surrogate technique. Furthermore, observable of surrogate reactions can be calculated. It is found that spin distributions of compound nuclei produced in O+U O+U reactions are equivalent and much less than 10, therefore satisfy conditions proposed by Chiba and Iwamoto if they are used as a pair in the surrogate ratio method.